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 Replies: 13 / Views: 1,697 |
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Valued Member
United States
68 Posts |
I've been working my way through the coins my grandmother left me and I am having a blast! The US coins are mostly in Whitman or Dansco folders, and the rest in rolls or loose in cigar boxes. There are also a bunch of world coins in those PVC pages in binders. These coins, particularly the copper ones, feel slimy to the touch or have an obvious sticky feeling surface. Some coins have green stuff in them. I have read that acetone does not usually harm coins. If I choose to use acetone to clean them, will soaking alone be enough to get rid of the slimy, sticky stuff, or would I also need to rub the surface of the coins gently with a Q-Tip or between my fingers? Most of the coins appear to be pre 1986 European, with none of them earlier than 1936. Thanks. Edited by Aurelius
09/10/2023 9:50 pm
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Bedrock of the Community
 United States
24981 Posts |
Aurelius, acetone will not harm these coins. Give them a good soak in acetone, pour the acetone and repeat. A final rinse may be required. And avoid rubbing if possible!
Inordinately fascinated by bits of metal with strange markings and figures
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Bedrock of the Community
United States
73756 Posts |
Hondo Boguss explained what to do pretty well. Also, there's this stuff called Verdi-Care that can remove verdigris.
Errers and Varietys.
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Pillar of the Community
United States
883 Posts |
light swipes with an acetone soaked cotton ball, if needed after soaking alone, can help without doing too much to the coins
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Bedrock of the Community
Australia
21786 Posts |
If the slimy or sticky gunk will not come off after a very long acetone soak, then
OK to give a light rub if coins are in lesser grades, then allow them to completely dry out.
Risk: If the the sticky or gunky remains after a long acetone soak, gentle rub and long time to dry, there is a possibility that they may remain that way permanently, but in almost all cases, that shouldn't happen.
Although acetone is a very strong organic solvent,
it won't completely dissolve all organic substances, and in a a very small number of cases, only partially dissolves the target gunk.
I suspect that in these rare cases, the acetone has chemically reacted with the organic substance, rather than dissolving it.
Remember, some organic substances are also acidic, such as fatty acid cooking oils fats and skin oils, and can react with the metal surface, especially with copper or bronze coins. That is why fingerprints have to be removed from coins immediately, with acetone before chemical reaction with the metal surface of the coin takes effect.
Edited by sel_69l
09/11/2023 05:43 am
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Moderator
United States
56855 Posts |
Aurelius, If you are new to conserving coins best to only soak in 100% pure acetone. No cotton balls or q-tips, cotton is abrasive. Rose thorns can be used as picks "if" you know what you are doing. No microsoft cloth. Practice on junk coins first. John1  misspelled cloth  |
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Valued Member
United States
354 Posts |
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No microsoft clothes John, what do you have against Bill Gates?  |
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Moderator
United States
56855 Posts |
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what do you have against Bill Gates A few things,but I won't go there. Isn't that really soft cloth called microsoft?Or is it microfiber cloth? John1 |
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Moderator
United States
187702 Posts |
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Or is it microfiber cloth? This.  And while they are good for cleaning glass and automobiles, never rub coins with them. |
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Pillar of the Community
 United States
6464 Posts |
Just a note because nobody specifically mentioned it: acetone is not particularly safe for your skin in large amounts. You don't want to get fingerprints on your coins anyway. Use something else to pick the coins out of the acetone bath. I use a pair of soft wooden food skewers like chopsticks. In addition to the acetone, you are also dissolving a bunch of unknown crud into the liquid from the coin surfaces. You don't want that stuff on your fingers.
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Valued Member
 United States
68 Posts |
I dipped some of the coins in acetone as described an it made such a difference. None of the coins I dipped feel sticky or slimly any more. I did order some Verdi-Care for the few coins with heavy green stuff on them. I did find some older coins from the Italian states in the album, but I won't give them any treatment until I have researched their value.
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Moderator
Australia
16808 Posts |
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...No cotton balls or q-tips, cotton is abrasive... Cotton itself isn't abrasive to coins (unless we're talking delicate mirrored or proof surfaces, in which case everything is abrasive). The main reason we counsel against using cotton swabs, or "rubbing" while cleaning generally, is what the cotton might pick up. Suppose there's a tiny piece of grit, or sand, or something else hard that's embedded in the goo that's stuck onto the coin. The cotton swab removes the goo okay, but the bits of grit are picked up by the swab, and these bits of grit are then scraped along the coin's surface, leaving a tiny scratch-line behind. This is the "abrasiveness" that is to be avoided. Personally, for more stubborn goo spots I prefer to use an eyedropper or Pasteur pipette to squirt a jet of acetone onto the spot, rather than rubbing. That being said, for heavily worn coins, using a cotton swab isn't going to make much of a difference to the coin's condition. It's just good to not get into that habit. Quote:
Just a note because nobody specifically mentioned it: acetone is not particularly safe for your skin in large amounts. You don't want to get fingerprints on your coins anyway. Use something else to pick the coins out of the acetone bath. Here, I would agree with the conclusions - to avoid touching the acetone bath with your fingers - but not for the reasons stated. The reason you want to avoid putting your fingers in the acetone is the acetone will suck the fingerprint oil right out of your fingertips, and that dissolved oil will then get deposited onto the coin once the acetone evaporates. After all, the goal here is to completely remove the organic goo from your coins, not to take off the old organic goo and replace it with a fresh layer of organic goo. Disposable gloves might protect your nasty fingerprint oil from contaminating your nice clean acetone, but you'd need to make sure the gloves themselves are acetone-resistant or you end up causing the same problem. Many plastics and rubbers will depolymerize in acetone. Brandmeister's idea of wood or bamboo chopsticks is a good one, especially if you are skilled in using such tools. Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Valued Member
United States
68 Posts |
Thanks for all the tips and suggestions. It looks like I have my work cut out for me! I came across another album of mostly copper type coins and they are all slimy. I have removed them and thrown away those PVC sleeves. Yuck!
Edited by Aurelius
09/16/2023 10:25 pm
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Pillar of the Community
United States
883 Posts |
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Replies: 13 / Views: 1,697 |
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Posted 09/10/2023 11:28 pm
